Wednesday, October 26, 2005

Windpower Microgeneration: Home Wind Turbines

According to BBC News household windmills are becoming quite the fashion, but they ask can they make money?

Domestic wind turbines have been described as "the new handbags" - the latest luxury items craved by those who want to be first to try new technology. But this description overlooks their green credentials, because any electricity powered by the elements is reducing CO2 emissions, which are blamed for global warming. And there are also the financial motivations.

A household with a windmill can save money on bills and sell excess electricity back to the national grid. So could wind turbines become a nice little earner?

They are certainly on the increase - 7,000 households have been given grants to get the turbines installed.

A report this week by the Sustainable Consumption Roundtable envisages a future where households generate their electricity at home, using wind, solar and heat energy - but only if the government bought panels and turbines in large quantities for public buildings, so costs fall.

"Then we could all afford them," says Alan Knight, the group's chairman. "To install a generator or solar panel today you need specialist help. You should be able to buy one at B&Q [the UK equivalent of Home Depot - James] and stick it in yourself."

Turbines come in a range of sizes, prices and powers, and living close to neighbours can make planning permission problematic.

David Nisbet put up a 6kw turbine in his Essex garden in May, after overcoming 22 planning objections from neighbours about noise and visual impact. It is 11.5m high to the tip of the blade and it cost him £10,000 ($17,500) , plus a £5,000 grant.

His motivation was both financial and environmental and he was inspired by seeing two windmills at the Ford auto plant where he works.

Although he says the concerns of others have been allayed, the first few months haven't been as windy as he hoped.

"In the last eight to 10 years we've had strong south-westerly winds but not this year," he says. "It's been fickle and I'd put this six months down as a lean year.

"It's been generating electricity but not as much as I had hoped for. It's connected to the grid and any surplus flows back into the grid."

The wind provided 80% of his electricity in the summer and he estimates it will heat the house through winter, thereby saving him a total of £1,000 a year ($1,750) in heating bills. In 10 years, he hopes to have paid off his investment, but he will still have been buying electricity from the grid during that time.

It isn't possible to be totally dependent on wind because it doesn't blow every minute, says Alison Hill at the British Wind Energy Association.

"You may get the 4-5,000 units a year to run a household but not every single hour of every day so you would need to have standard electricity grid connection to get electricity from the grid.

"We are quite lucky in the UK because when we have most wind we have most demand - winter. That profile of generation is quite beneficial, but no-one can have 100% self-sufficiency on wind alone.

"If it looks like you have a big wind resource and a good turbine, you can connect that turbine to the grid and sell that, so there's an additional revenue for householders there.

"Typically, a household sees a reduction of between a quarter and a third in its annual electricity bill."

Solar panels can supplement wind to boost a home's renewable sources but some households do claim to make a profit purely from wind, by generating so much electricity that the amount they sell back is greater than the amount they buy.

That would require a very energy-efficient house and living in a particularly windy part of the UK, says Ms Hill.

And the future is bright - despite the end of government grants in February - because big companies like British Gas are investing in new kinds of turbines which have yet to come on the market, she adds.BBC News Article

19 Comments:

James, great blog. I have a question. My husband and I plan to build a house someday and we are really considering going totally solar power. Now, I was reading in an astronomy text that one solar flare could power the entire USA at our current rate for 100,000 years. That put things in perspective for us. We are in the US, but for some reason (can you guess?) solar power just isn't touted as a great means. But honestly I think it's one of the best means. What do you think?

jessica: I know you're talking to James, but this is a topic that I care deeply about.

Have you thought about having multiple green energy "doodads"? You could have photovoltaic cells for sunny days, and a wind turbine for windy (possibly not sunny) days, and a solar/geothermal heater. I will posting on my blog an essay on 'green homes' soon- I want it to be well crafted. :) good luck with building the house!-titanium

So, if you have a huge garden, and can afford 10 thousand pounds, and are happy to take an extra 5 thousand pounds from the humble taxpayer, you can buy a wind turbine that delivers 80% of your summer electricity requirement. The hope that the turbine will heat the house over the winter can only be maintained by the inumerate. 80% of the average UK houshold electricity over three summer months equates to about 45 quid. I think a more realistic analysis would reveal that it will take somewhere between 5-10 years to pay back the energy of manufacture.

Interesting blog ! I live in Norway, an almost 100% hydro power country so far, but now wind power is gaining progress. Do you have any idea where one can get info about the manufacturers of such micro mills ??

This is along the lines of thinking I have advocated for my area (I live on the Oregon Coast of the US.) We get strong storms and breezes a good part of the year, especially when it isn't sunny out. Coupled with efficiency measures, solar panels for our drier, less windy summer days and pumped hydro storage, I think local electrical sustainability is possible.

Why pumped hydro?

Wind and water are erratic resources, but hydro is not. Our geography is such that you can go from sea level to more than a hundred meters in vertical elevation in less than 250M of horizontal distance. The excess sun and wind power could be directed to run pumps to push seawater up to holding tanks until the sun or wind stops supplying sufficient power. The pump could be shut off and water flow back to the ocean generating power until either the sun came out or wind started blowing.

Don't forget the classic characters up at www.otherpower.com — they give you instructions for making wind turbines out of a local tree trunk, brake disks, some wire and magnets... not 80% of your electricity, unless you already live like a Hobbit and just need some juice to connect to the net. But hey, if you are in an eco-village somewhere, go for it!

"In 10 years, he hopes to have paid off his investment, but he will still have been buying electricity from the grid during that time."

If in 10 years, he has saved 10,000 quid, that doesn't mean he broke even, because he lost the opportunity cost of that money. A realistic measure would be to consider how long it would take to pay off that mortgage on the turbine with a payment equal to the savings. For the sake of argument, I'll use their numbers (10,000 initial cost and 1,000 a year), and a rate of 6%, with monthly payments. That gives you 184 month, or 15 1/3 years. If we include the gov't subsidy, we're talking a payoff of 462 months, or 38.5 years. Yikes!

I imagine that calculation might depend on the future cost of electricity, and 10 or 20yrs out, who knows what that could be. If enough people bought turbines, the price of home heating oil might drop to make these years to payoff more than 40yrs.But I think its a good idea just on the basis of individual assertion. Take back some of the playing field that is dominated by MNC. Even if there is no wind or sunshine in your part of the country, hook up that generator behind the windmill to a treadmill and get fit while you take control of your energy production and consumption.This doesn't work so well for older coggers like me, but it'll atleast get those joggers off my sidewalks.

You may lose the opportunity cost.. but that assumes you would find a better opportunity. I don't know about you, but I'm not a very good stock picker, so we invested in a 4kw grid-tied PV system. We get around $1k per year, or nearly 7% per year in "dividends" on our "investment". That's not bad IMHO.

You could also call it insurance against rate hikes, not to mention computer crashes and appliance failure due to low-quality grid power, all of which we had to deal with before installing our PV system.

If anyone's interested you can check out my page for a writeup on our system.

Very interesting blog. I'm a Spanish blogger and I've been following you for few weeks. This is the second post I link in my blog. I can't do trackback so I've post you a comment.On the other hand, I'm a real fan of the household windmills and similiar local technologies.I don't know how the regulation in UK is, but I think in Spain is one of the objection to beat, not only de price, the grants or the bonus for the electricity sales

Hi,I am from the south-Indian state of Kerala. I have been thinking about alternate electricity mainly because two reasons. One is the bill is very high and the other is the bueaucratic attitude of the employees working in the Electric companies which is 99% Govt. You get bills which is sometimes 5 times higher than your consumption. You cannot argue/verify and get the money back, they install meters mostly faulty and with inaccurate readings. A normal home as to pay sometimes USD 300 per month for the bill which is very very high compare to the other part of India. Main reasons are the above. So, I am looking for good alternate electricity options for the home - we have good sunlight a normal windy climate.

Now solar and wind technologies are getting better every year thanks to nanotechnogolies. But electricity production is not the most important. IF YOU PLAN TO BUILD A HOUSE GO FOR SOLAR-PASSIVE ONE. With special double insulation and heat recovery ventilation system it will cut energy needs to 10-20% of typical household. So wind and solar will be more than enough. 6kW turbine is very big one. 3kW should be enough for 3 bedroom house.

If I remember my High School Geometry correctly, a micro-windmill will probably never be very efficient. The radius of the turbine blades determines the amount of power generated (pi x radius squared) and that would mean that the secret would be to get the longest possible blades. Yet the idea of a mini-turbine defeats the logic of Geometry. It would be better to pool 100 people together and build one huge wind turbine than 100 little ones. The difference in the power generated from one large turbine and 100 smaller ones would be exponentially greater--and suddenly make the whole thing work. The mini-turbine is impractical; but pooling 100 people at $10,000.00 each would allow the erection of a single 42 meter three-bladed very efficient turbine. Why not form some sort of co-operative to get 100 people each to contribute $10,000.00 and really make some progress?

- How do you sell back onto the grid - is anyone actually doing this already?- Aren't there some physical constraints on who can use the elkectricity that is pushed back onto the grid?- Is there currently a market for selling electricity back to the grid ( ie: what price do you get, how does the price vary, and how do you verify that you have been paid correctly for the electricityyou on-sell?

I've scoured the WWW to try and find some description fo how this works and found nothing. Anything you can link me to is appreciated.

Hi James,I have a question concerning home /windpower generation: How do you connect to the low tension grid? How do yow know when you are putting power to the grid and when you are taking from it?What do you think?